Chad W. Washington and Robert L. Grubb Jr.
More than 1.5 million Americans suffer a traumatic brain injury (TBI) each year. Seventy-five percent of these patients have a mild TBI, with Glasgow Coma Scale (GCS) Score 13–15. At the authors' institution, the usual practice has been to admit those patients with an associated intracranial hemorrhage (ICH) to an ICU and to obtain repeat head CT scans 12–24 hours after admission. The purpose of this study was to determine if there exists a subpopulation of mild TBI patients with an abnormal head CT scan that requires neither repeat brain imaging nor admission to an ICU. This group of patients was further classified based on initial clinical factors and imaging characteristics.
A retrospective review of all patients admitted to a Level I trauma center from January 2007 through December 2008 was performed using the hospital Trauma Registry Database, medical records, and imaging data. The inclusion criteria were as follows: 1) an admission GCS score ≥ 13; 2) an isolated head injury with no other injury requiring ICU admission; 3) an initial head CT scan positive for ICH; and 4) an initial management plan that was nonoperative.
Collected data included age, etiology, initial GCS score, time of injury, duration of ICU stay, duration of hospital stay, and anticoagulation status. Primary outcomes measured were the occurrence of neurological or medical decline and the need for neurosurgical intervention. Imaging data were analyzed and classified based on the predominant blood distribution found on admission imaging. Data were further categorized based on the Marshall CT classification, Rotterdam score, and volume of intraparenchymal hemorrhage (IPH). Progression was defined as an increase in the Marshall classification, an increase in the Rotterdam score, or a 30% increase in IPH volume.
Three hundred twenty-one of 1101 reviewed cases met inclusion criteria for the study. Only 4 patients (1%) suffered a neurological decline and 4 (1%) required nonemergent neurosurgical intervention. There was a medical decline in 18 of the patients (6%) as a result of a combination of events such as respiratory distress, myocardial infarction, and sepsis. Both patient age and the transfusion of blood products were significant predictors of medical decline. Overall patient mortality was 1%.
Based on imaging data, the rate of injury progression was 6%. The only type of ICH found to have a significant rate of progression (53%) was a subfrontal/temporal intraparenchymal contusion. Other variables found to be significant predictors of progression on head CT scans were the use of anticoagulation, an age over 65 years, and a volume of ICH > 10 ml.
Most patients with mild TBI have a good outcome without the necessity of neurosurgical intervention. Mild TBI patients with a convexity SAH, small convexity contusion, small IPH (≤ 10 ml), and/or small subdural hematoma do not require admission to an ICU or repeat imaging in the absence of a neurological decline.
Chad W. Washington, Kathleen E. McCoy and Gregory J. Zipfel
Cavernous malformations (CMs) are angiographically occult, low-pressure neurovascular lesions with distinct imaging and clinical characteristics. They present with seizure, neurological compromise due to lesion hemorrhage or expansion, or as incidental findings on neuroimaging studies. Treatment options include conservative therapy, medical management of seizures, surgical intervention for lesion resection, and in select cases stereotactic radiosurgery. Optimal management requires a thorough understanding of the natural history of CMs including consideration of issues such as mode of presentation, lesion location, and genetics that may impact the associated neurological risk. Over the past 2 decades, multiple studies have been published, shedding valuable light on the clinical characteristics and natural history of these malformations. The purpose of this review is to provide the reader with a concise consolidation of this published material such that they may better understand the risks associated with CMs and their implications on patient treatment.
Manjul Tripathi, Pravin Salunke and Kanchan Kumar Mukherjee
Chad W. Washington, L. Ian Taylor, Robert J. Dambrino, Paul R. Clark and Gregory J. Zipfel
The Agency of Healthcare Research and Quality (AHRQ) has defined Patient Safety Indicators (PSIs) for assessments in quality of inpatient care. The hypothesis of this study is that, in the treatment of unruptured cerebral aneurysms (UCAs), PSI events are less likely to occur in hospitals meeting the volume thresholds defined by The Joint Commission for Comprehensive Stroke Center (CSC) certification.
Using the 2002–2011 National (Nationwide) Inpatient Sample, patients treated electively for a nonruptured cerebral aneurysm were selected. Patients were evaluated for PSI events (e.g., pressure ulcers, retained surgical item, perioperative hemorrhage, pulmonary embolism, sepsis) defined by AHRQ-specified ICD-9 codes. Hospitals were categorized by treatment volume into CSC or non-CSC volume status based on The Joint Commission’s annual volume thresholds of at least 20 patients with subarachnoid hemorrhage and performance of 15 or more endovascular coiling or surgical clipping procedures for aneurysms.
A total of 65,824 patients underwent treatment for an unruptured cerebral aneurysm. There were 4818 patients (7.3%) in whom at least 1 PSI event occurred. The overall inpatient mortality rate was 0.7%. In patients with a PSI event, this rate increased to 7% compared with 0.2% in patients without a PSI event (p < 0.0001). The overall rate of poor outcome was 3.8%. In patients with a PSI event, this rate increased to 23.3% compared with 2.3% in patients without a PSI event (p < 0.0001). There were significant differences in PSI event, poor outcome, and mortality rates between non-CSC and CSC volume-status hospitals (PSI event, 8.4% vs 7.2%; poor outcome, 5.1% vs 3.6%; and mortality, 1% vs 0.6%). In multivariate analysis, all patients treated at a non-CSC volume-status hospital were more likely to suffer a PSI event with an OR of 1.2 (1.1–1.3). In patients who underwent surgery, this relationship was more substantial, with an OR of 1.4 (1.2–1.6). The relationship was not significant in the endovascularly treated patients.
In the treatment of unruptured cerebral aneurysms, PSI events occur relatively frequently and are associated with significant increases in morbidity and mortality. In patients treated at institutions achieving the volume thresholds for CSC certification, the likelihood of having a PSI event, and therefore the likelihood of poor outcome and mortality, was significantly decreased. These improvements are being driven by the improved outcomes in surgical patients, whereas outcomes and mortality in patients treated endovascularly were not sensitive to the CSC volume status of the hospital and showed no significant relationship with treatment volumes.
Chad W. Washington, Colin P. Derdeyn, Ralph G. Dacey Jr., Rajat Dhar and Gregory J. Zipfel
Studies using the Nationwide Inpatient Sample (NIS), a large ICD-9–based (International Classification of Diseases, Ninth Revision) administrative database, to analyze aneurysmal subarachnoid hemorrhage (SAH) have been limited by an inability to control for SAH severity and the use of unverified outcome measures. To address these limitations, the authors developed and validated a surrogate marker for SAH severity, the NIS-SAH Severity Score (NIS-SSS; akin to Hunt and Hess [HH] grade), and a dichotomous measure of SAH outcome, the NIS-SAH Outcome Measure (NIS-SOM; akin to modified Rankin Scale [mRS] score).
Three separate and distinct patient cohorts were used to define and then validate the NIS-SSS and NIS-SOM. A cohort (n = 148,958, the “model population”) derived from the 1998–2009 NIS was used for developing the NIS-SSS and NIS-SOM models. Diagnoses most likely reflective of SAH severity were entered into a regression model predicting poor outcome; model coefficients of significant factors were used to generate the NIS-SSS. Nationwide Inpatient Sample codes most likely to reflect a poor outcome (for example, discharge disposition, tracheostomy) were used to create the NIS-SOM.
Data from 716 patients with SAH (the “validation population”) treated at the authors' institution were used to validate the NIS-SSS and NIS-SOM against HH grade and mRS score, respectively.
Lastly, 147,395 patients (the “assessment population”) from the 1998–2009 NIS, independent of the model population, were used to assess performance of the NIS-SSS in predicting outcome. The ability of the NIS-SSS to predict outcome was compared with other common measures of disease severity (All Patient Refined Diagnosis Related Group [APR-DRG], All Payer Severity-adjusted DRG [APS-DRG], and DRG).
The NIS-SSS significantly correlated with HH grade, and there was no statistical difference between the abilities of the NIS-SSS and HH grade to predict mRS-based outcomes. As compared with the APR-DRG, APSDRG, and DRG, the NIS-SSS was more accurate in predicting SAH outcome (area under the curve [AUC] = 0.69, 0.71, 0.71, and 0.79, respectively).
A strong correlation between NIS-SOM and mRS was found, with an agreement and kappa statistic of 85% and 0.63, respectively, when poor outcome was defined by an mRS score > 2 and 95% and 0.84 when poor outcome was defined by an mRS score > 3.
Data in this study indicate that in the analysis of NIS data sets, the NIS-SSS is a valid measure of SAH severity that outperforms previous measures of disease severity and that the NIS-SOM is a valid measure of SAH outcome. It is critically important that outcomes research in SAH using administrative data sets incorporate the NIS-SSS and NIS-SOM to adjust for neurology-specific disease severity.
Jacob K. Greenberg, Chad W. Washington, Ridhima Guniganti, Ralph G. Dacey Jr., Colin P. Derdeyn and Gregory J. Zipfel
Hospital readmission is a common but controversial quality measure increasingly used to influence hospital compensation in the US. The objective of this study was to evaluate the causes for 30-day hospital readmission following aneurysmal subarachnoid hemorrhage (SAH) to determine the appropriateness of this performance metric and to identify potential avenues for improved patient care.
The authors retrospectively reviewed the medical records of all patients who received surgical orendovas-cular treatment for aneurysmal SAH at Barnes-Jewish Hospital between 2003 and 2013. Two senior faculty identified by consensus the primary medical/surgical diagnosis associated with readmission as well as the underlying causes of rehospitalization.
Among 778 patients treated for aneurysmal SAH, 89 experienced a total of 97 readmission events, yielding a readmission rate of 11.4%. The median time from discharge to readmission was 9 days (interquartile range 3–17.5 days). Actual hydrocephalus or potential concern for hydrocephalus (e.g., headache) was the most frequent diagnosis (26/97, 26.8%), followed by infections (e.g., wound infection [5/97, 5.2%], urinary tract infection [3/97, 3.1%], and pneumonia [3/97, 3.1%]) and thromboembolic events (8/97, 8.2%). In most cases (75/97, 77.3%), we did not identify any treatment lapses contributing to readmission. The most common underlying causes for readmission were unavoidable development of SAH-related pathology (e.g., hydrocephalus; 36/97, 37.1%) and complications related to neurological impairment and immobility (e.g., thromboembolic event despite high-dose chemoprophylaxis; 21/97, 21.6%). The authors determined that 22/97 (22.7%) of the readmissions were likely preventable with alternative management. In these cases, insufficient outpatient medical care (for example, for hyponatremia; 16/97, 16.5%) was the most common shortcoming.
Most readmissions after aneurysmal SAH relate to late consequences of hemorrhage, such as hydrocephalus, or medical complications secondary to severe neurological injury. Although a minority of readmissions may potentially be avoided with closer medical follow-up in the transitional care environment, readmission after SAH is an insensitive and likely inappropriate hospital performance metric.
L. Ian Taylor, James C. Dickerson, Robert J. Dambrino, M. Yashar S. Kalani, Philipp Taussky, Chad W. Washington and Min S. Park
Although the use of dual antiplatelet therapy with flow diversion is recommended and commonplace, the testing of platelet inhibition is more controversial.
The authors reviewed the medical literature to establish and describe the physiology of platelet adhesion, the pharmacology of antiplatelet medications, and the mechanisms of the available platelet function tests. Additionally, they present a review of the pertinent neurointerventional and interventional cardiology literature.
Competing reports in the neurointerventional literature argue for and against the use of routine platelet function testing, with adjustments to the dosage or medications based on the results. The interventional cardiology literature has also wrestled with this dilemma after percutaneous coronary interventions, with conflicting reports of the benefits of platelet function testing.
Despite its prevalence, the benefits of platelet function testing prior to flow diversion are unproven. This practice will likely remain controversial until the level of evidence improves through more rigorous testing and reporting.